"It has been a long wait for Adam, but we are thrilled to see him justly rewarded," USA Track and Field chief executive Max Siegel said.

"Adam is one of the greatest shot putters in history. Adding this Olympic gold medal to his 2005 world championship, 2000 Olympic silver medal and countless other medals and honours only reinforces his already-impressive legacy."

Bilonoh was found positive for steroids when a 2004 drug sample was retested last year.

Denmark's Joachim Olsen moved into Nelson's former silver medal spot while Spain's Manuel Martinez moved up to claim the bronze medal.